Demo saves and character unlocks
Demo progress and character unlocks will not transfer to the full game.
The reason is the difference in progression: the demo does not include the full level progression system, so its save data will not carry over.
Plan your demo session
Play the Carthage demo to try the game before launch. Do not plan a full-game starting roster around unlocks earned in the demo.
This policy concerns the move from the Steam demo to the full game. Cross-platform saves and saving or restoring a run are separate features. The demo removal plan also does not specify whether an already installed copy will remain playable.